<!-- eslint-disable vue/valid-template-root -->
<template>
  <div class="todo-footer" v-if="total">
    <label>
      <!-- <input type="checkbox" :checked="isAll" @change="checkAll"/> -->
      <input type="checkbox" v-model="isAll"/>
    </label>
    <span> <span>已完成{{ doneTotal }}</span> / 全部{{total}} </span>
    <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  props: ["todos","checkAllTodo","clearAllTodo"],
  computed: {
    total(){
      return this.todos.length;
    },
    doneTotal() {
      //第一种
      // let i = 0
      // this.todos.forEach((todo) => {
      //   if(todo.done) i++;
      // });
      // return i;
      //第二种
      // return this.todos.filter((todo) => todo.done).length;
      //第三种
      return this.todos.reduce((pre, todo) => pre + (todo.done ? 1 : 0), 0);

    },
    isAll:{
      get(){
        return this.doneTotal === this.total && this.total > 0;
      },
      set(value){
        this.checkAllTodo(value);
      }
      
    }
  },
  methods:{
    // checkAll(e){
    //   // console.log(e.target.checked);
    //   this.checkAllTodo(e.target.checked);
    // }
    clearAll(){
      this.clearAllTodo();
    }
  }
};
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>